Feign动态请求的方式比较好用的有两种，一种是通过注解+URI类实现，另一种是通过builder构建Api的方式实现。

注解 + URI

1.定义接口路径

FeignClient注解中的url是默认路径，实际上调用已URI中的url为准。

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;

import java.net.URI;

@FeignClient(name = "system", url = "http://${server.haproxy.ip}:${server.haproxy.port}")
public interface VbngSystemApi {

    @GetMapping("/api/v2/system")
    Object getSystem(URI uri);

    @GetMapping("/api/v2/aaasss")
    Object getAaa(URI uri);
}

2.调用接口

我们只需要设置好URI就会请求我们想要的接口啦~

/**
 * @ClassName SystemInfoService
 * @Author Lijw
 * @Date 2021/3/8 10:35
 * @Description
 **/
@Slf4j
@Service
public class SystemInfoService<T> {
    @Autowired
    VbngSystemApi vbngSystemApi;

    public static URI getUri(String ip, Integer port) {
        try {
            return new URI("https", null, ip, port, null, null, null);
        } catch (URISyntaxException e) {
            String msg = String.format("URI is wrong!,ip:[%s],port:[%s],e:[%s]", ip, port, e);
            log.error(msg);
            throw new AemsException(msg);
        }
    }

    public void get() {
        URI uri = getUri("127.0.0.1", 8080);
        Object system = vbngSystemApi.getSystem(uri);
    }

}

第二种

1.定义接口

import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import feign.Param;
import feign.RequestLine;
import org.springframework.cloud.openfeign.FeignClient;

import java.util.HashMap;

/**
 * @ClassName VbngPerformanceApi
 * @Author Lijw
 * @Date 2021/2/20 16:06
 * @Description
 **/
@FeignClient(name = "vBNG")
public interface VbngPerformanceApi {

    @RequestLine("GET /api/v2/cpuMemory")
    JSONObject cpuMemory();

    @RequestLine("GET /api/v2/system")
    HashMap system();

}

2.调用接口

skipSSLClient客户端是自己实现的跳过SSL认证用于请求Https接口的类。（如果不需要使用https则可以构建世不设置client）

FeignClientsConfiguration需要导入其中包含编码器，解码器等一系列默认参数。

因为可能会频繁的创建Feign客户端所以用guava的cache做了一个缓存，不需要也可以不用。

/**
 * @ClassName PerformanceDataHandle
 * @Author Lijw
 * @Date 2021/2/20 15:59
 * @Description
 **/
@Slf4j
@Component
@Import(FeignClientsConfiguration.class)
public class PerformanceDataHandle {

    @Autowired
    Decoder decoder;
    @Autowired
    Encoder encoder;
    @Autowired
    Client skipSSLClient;

    @Autowired
    PerformanceServiceApi performanceServiceApi;

    public final static Cache<String, VbngPerformanceApi> FEIGN_CACHE_MAP = CacheBuilder.newBuilder()
            .maximumSize(100000)
            .expireAfterWrite(3, TimeUnit.HOURS)
            .build();


    public VbngPerformanceApi getFeign(String url) {
        return Optional.ofNullable(FEIGN_CACHE_MAP.getIfPresent(url))
                .orElseGet(() -> {
                    var api = Feign.builder()
                            .client(skipSSLClient)
                            .encoder(encoder).decoder(decoder)
                            .options(new Request.Options(60000, 60000))
                            .retryer(new Retryer.Default(5000, 5000, 3))
                            .logLevel(Logger.Level.BASIC)
                            .target(VbngPerformanceApi.class, url);
                    FEIGN_CACHE_MAP.put(url, api);
                    return api;
                });
    }

    public static String getUrl(String ip, Integer port) {
        Assert.isTrue(IpV4Util.ipV4Validate(ip), String.format("IP address not conforming to specification! ip:[%s]", ip));
        return "https://" + ip + ":" + port;
    }

    public void get() {
        String url = getUrl("127.0.0.1", 8080);
        VbngPerformanceApi feign = getFeign(url);
        HashMap system = feign.system();
    }

}

代码有待改进，欢迎提出不足🤡